Assessing Bovine Exposure and IgE Levels Among Dairy Workers Using a Risk Matrix

Dairy workers face a range of occupational risks and outcomes, including acute and chronic respiratory hazards. However, the evidence for negative respiratory outcomes is mixed. Thus, more research is needed to understand the connection between occupational exposures and health outcomes on dairy farms to facilitate the development, implementation, and evaluation of improved programs and processes for injury and illness prevention. This study contributes to this need by evaluating the association between exposure risk and bovine-specific immunoglobulin (Ig)E levels among dairy workers.

Dairy workers (n = 36) self-reported time spent in various dairy-related tasks, as well as personal protective equipment used during all tasks. This information was used to develop job risk matrices for each task and all tasks combined. Serum bovine dander IgE levels were determined for all participants, and the association between exposure and IgE was assessed.

Seven participants (19.4%) had an elevated bovine IgE level. Those with elevated IgE had a mean total risk matrix score of 9.0 compared to 7.6 for those without elevated IgE. In the adjusted models, there were no statistically significant associations between IgE levels and bovine allergen risk matrix scores. However, for the task of herd health, a one-point increase in the bovine allergen risk matrix score was associated with a 1.42 kU/L increase in anti-bovine IgE (p = .08).

This work shows the feasibility of using a semi-quantitative task risk matrix to more formally conceptualize dairy worker occupational exposure risk to a respiratory hazard. While not statistically significant, this study identified a positive association between performing herd health tasks and having elevated bovine IgE levels. This suggests task risk matrix approaches may be useful in studying other respiratory hazards in dairy production, including infectious agents.